Today In Science History – December 2 – Chicago Pile 1

Sketch of the Chicago Pile-1 Reactor at Stagg Field at the University of Chicago in 1942.

December 2 is the anniversary of the first artificial sustained atomic chain reaction. The Chicago Pile 1 atomic pile was constructed as part of the secret Manhattan Project to test the possibility of achieving an atomic chain reaction that could be controlled and sustained. The pile was a massive construction using 771,000 pounds of graphite, 80,590 pounds of uranium oxide and 12,400 pounds of uranium metal. Three sets of cadmium control rods were used to regulate the flow of neutrons. One set was an automatic setting that could be controlled from the control room. Another set acted as a safety that was heavily weighted to fall back into the pile when a supporting rope was cut by a man stationed nearby with an axe. The third set of rods was hand controlled and was the actual set used to initiate the experiment.

The men spent the morning initiating tests of the system to lead up to the actual chain reaction. The final test achieved the critical self-sustaining chain reaction they were trying for. They allowed their reactor to operate for 28 minutes before shutting it down. It was the first time atomic energy was used and controlled and one of the most important events leading into the Atomic Age.

Notable Science History Events for December 2

1987 – Luis Federico Leloir died.

Luis Federico Leloir (1906 – 1987)

Leloir was an Argentine physician and biochemist who was awarded the 1970 Nobel Prize in Chemistry for the discovery of sugar nucleotides and their role in carbohydrate biosynthesis.

He researched the way the body breaks down and forms lactose and discovered sugar nucleotides. These are important parts of the process the body converts sugar to usable energy.

1942 – First sustained atomic chain reaction achieved.

1885 – George Richards Minot was born.

George Minot (1885 – 1950)Nobel Foundation

Minot was an American physician who shares the 1934 Nobel Prize in Medicine with George Whipple and William Murphy for their research into anemia and liver therapy. Whipple had shown that pernicious anemia in dogs could be treated by feeding them raw liver. Minot prepared liver extracts that became the primary treatment for human anemia until the vital compound in liver was identified as vitamin B12.